• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.237-240
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• 2001

In this paper, we have presented processing technique about wet etching for silicon membrane construction formation. In order to make selective etching of backside silicon wafer, we used Si$_3$N$_4$ layer by PECVD(Plasma Enhanced Chemical Vapor Deposition). We have measured the surface thickness in backside silicon wafer after anisortropic wet etching with KOH:distilled water solutions. Through this experiment, we acquired the etching rate for 1.29${\mu}{\textrm}{m}$/min. The average rough of Si-membrane frontside and backside was 0.26${\mu}{\textrm}{m}$, 0.90${\mu}{\textrm}{m}$, respectively.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.193-197
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• 2017

In this study, we report on the catalyst process installed in conjunction with a wet plasma electrostatic precipitator to remove the oil mist and fine dust emitted from large-size grill restaurants. The multi-stage catalyst module reduced odor through catalytic reaction of acetaldehyde on catalysts even at an ambient temperature with ozone as an oxidant readily produced in a wet plasma electrostatic precipitator. Two types of manganese-based catalysts, $Mn_2O_3$ and $CuMnO_x$ were fabricated by extrusion molding for structured catalysts in practical applications, and the optimum conditions for high removal efficiencies of acetaldehyde and ozone were determined. When two optimized catalysts were applied in a two-stage catalyst module, the removal efficiency of acetaldehyde and ozone were ${\geq}85%$ and 100% respectively at the space velocity of $10,000h^{-1}$ and the reaction temperature of $100^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.56 no.3
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• pp.211-232
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• 2019

Porous ceramics are promising materials for a number of functional and structural applications that include thermal insulation, filters, bio-scaffolds for tissue engineering, and preforms for composite fabrication. These applications take advantage of the special characteristics of porous ceramics, such as low thermal mass, low thermal conductivity, high surface area, controlled permeability, and low density. In this review, we emphasize the direct foaming method, a simple and versatile approach that allows the fabrication of porous ceramics with tailored microstructure, along with distinctive properties. The wet foam stability is achieved under the controlled addition of amphiphiles to the colloidal suspension, which induce in situ hydrophobization, allowing the wet foam to resist coarsening and Ostwald ripening upon drying and sintering. Different components, like contact angle, adsorption free energy, air content, bubble size, and Laplace pressure, play vital roles in the stabilization of the particle stabilized wet foam to the porous ceramics. The mechanical behavior of the load-displacements curves of sintered samples was investigated using Herzian indentations testes. From the collected results, we found that microporous structures with pore sizes from 30 ㎛ to 570 ㎛ and the porosity within the range from 70% to 85%.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.05a
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• pp.15-15
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• 1994

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1308-1315
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• 2001

This study was conducted to evaluate the effects of different methods of feeding and processing of diets on performance, morphological changes in the small intestine and nutrient digestibility of young pigs. A total of 120 pigs (Youkshire${\times}$Landrace${\times}$Duroc; initial body weight of $5.83{\pm}0.67kg$) were randomly allotted into six treatments in a $2{\times}3$ factorial design. Treatments were 1) dry feeding with a mash diet (DM), 2) dry feeding with a pelleted diet (DP), 3) dry feeding with an expanded crumble diet (DEC), 4) wet feeding with a mash diet (WM), 5) wet feeding with a pelleted diet (WP), 6) wet feeding with an expanded crumble diet (WEC). Average daily gain (ADG) and average daily feed intake (ADFI) were not significantly (p>0.05) different among treatments. However, feed conversion ratio (FCR) was significantly improved when pigs fed a pelleted diet or an expanded crumble diet. Pigs fed an expanded crumble diet showed 9.2% and 17.3% improvement in ADG and FCR compared with those fed a mash diet. The morphological changes in the small intestine were examined at the termination (4 weeks after weaning) of the experiment. Differences in morphological changes of gastrointestinal tract were not significant among treatments. Though villus height was not significantly affected by feeding method or feed processing, the villus height of weaned pigs tended to be preserved by wet feeding. The use of a pelleted diet also helped to prevent the shortening of villus height. Pigs fed a WP diet maintained the highest villus height at all parts of the small intestine. There was no significant difference (p>0.05) in nutrient digestibility among treatments. However, nutrient digestibility for pigs fed a pelleted diet had a higher than that of pigs fed mash diets. Especially, pigs fed a WP diet digested 5.3% more P each day than those fed a DM diet. Compared with the mash diet, the expanded crumble diet decreased feed cost per kg weight gain by 15%. The net profit per pig was 79% higher in the expanded crumble diet pigs than in mash diet pigs. In conclusion, this study suggests that feeding processed diets to piglets can be more beneficial in terms of FCR and production cost.

• Culinary science and hospitality research
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• v.12 no.2 s.29
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• pp.206-221
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• 2006

To establish an optimum formula for processing wet noodles with steam-dried Hizikia fusiformis flour(SHF), it was incorporated into wheat flour by the ratio of 0, 1, 3, 5, 10 and 20% based on a flour weight. Application of 2% mehthylcelluose(MC) to improve the texture of noodles mixed with SHF was also attempted. Evaluation was performed on the dough rheology and wet noodle quality, such as cooking characteristics, mechanical texture properties, sensory value and shelf-life. Water absorption rate of the composite flour increased linearly as the content of SHF increased from 1% to 10%, and noodle sheet-formation was also acceptable in the same content level. The weight and volume of cooked noodles were decreased, and turbidity of soup was, if exceeding more than 5% of SHF, increased constantly. However, these problems could be remarkably resolved in SHF plus 2% MC. Texture profile analysis of cooked noodles showed an increase of hardness, gumminess, and chewiness up to 5% SHF. The results of sensory evaluation showed that cooked noodles containing 5% SDF were acceptable as much as wheat four noodles in terms of color, texture, taste and flavor. Based on cooking properties, rheological and sensory evaluation, addition of 5% SHF plus 2% MC was suggested to be suitable for making wet noodles, of which the shelf-life was estimated to be 8 days at $5^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.56 no.5
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• pp.513-520
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• 2019

This study reports the improvement of mechanical properties of Al₂O₃ porous ceramics from colloidal suspension with the addition of carbon fiber by direct foaming. The initial colloidal suspension of Al₂O₃ was partially hydrophobized by surfactant to stabilize wet foam with the addition of carbon fiber from 2 to 8 wt% as stabilizer. The influence of carbon fiber on the air content, bubble size, pore size and pore distribution in terms of wet foam stability and physical properties of porous ceramics were discussed. The viscosity of the colloidal suspension was increased giving solid like properties with the increased in carbon fiber content. The mechanical properties of the sintered porous samples were investigated by Hertzian indentation test. The results show the wet foam stability of more than 90% corresponds to compressive loading of 156.48 N and elastic modulus of 57.44 MPa of sintered sample with 8 wt% of carbon fiber content.

• Journal of Ceramic Processing Research
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• v.20 no.6
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• pp.655-659
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• 2019

Calcium phosphates such as HA (hydroxyapatite), β-TCP (tricalcium phosphate) and biphasic HA/β-TCP, were synthesized by wet chemical precipitation in aqueous solution combined with ball milling process. Nanosize powders of the calcium phosphates were synthesized using Ca(OH)2 and H3PO4. The effects of initial precursor Ca/P ratio (1.30, 1.50 and 1.67), ball milling process and post heat-treatment on the phase evolution behavior of the powders were investigated. The phase of resulting powder was controllable by adjusting the initial Ca/P ratio. HA was the only phase for as-prepared powders in both cases of Ca/P ratios of 1.50 and 1.67. The single HA phase without any noticeable second phase was obtained for the initial Ca/P ratio of 1.67 in the overall heat-treatment range. Pure β-TCP and biphasic calcium phosphate (HA/β-TCP) were synthesized from precursor solutions having Ca/P molar ratios of 1.30 and 1.50, respectively, after having been heat-treated above 700 ℃. The β-TCP phase has appeared on the pre-existing DCPD (dicalcium phosphate dihydrate) and/or HA phase. Dense ceramics having translucency were obtained at a considerably lower sintering temperature. The modified process offered a fast, convenient and economical route for the synthesis of calcium phosphates.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.308-311
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• 2012

A wide range of possible hazards existing in thermal batteries are mainly caused by thermal runaway, which results in overheating or explosion in extreme case. Battery separators ensure the separation between two electrodes and the retention of ion-conductive electrolytes. Thermal runaways in thermal batteries can be significantly reduced by the adoption of these separators. The high operating temperature and the violent reactivity in thermal batteries, however, have limited the introduction of conventional separators. As a substitute for separators, MgO powders have been mostly used as a binder to hold molten salt electrolyte. During recent decades the fabrication technology of ceramic fiber, which has excellent mechanical strength and chemical stability, has undergone significant improvement. In this study we adopted wet-laid nonwoven paper making method instead of the electrospinning method which is costly and troublesome to produce in volume. Polymeric precursor can readily be coated on the surface of wet-laid ceramic paper, and be formed into ceramic film after heat treatment. The mechanical strength and the thermo-chemical stability as well as the wetting behaviors of ceramic separators with various molten salts were investigated to be applicable to thermal batteries. Due to their excellent chemical, mechanical, and electrical properties, wet-laid nonwoven separators made from ceramic fibers have revealed positive possibility as new separators for thermal batteries which operate at high temperature with no conspicuous sign of a short circuit and corrosion.

• Korean Journal of Metals and Materials
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• v.48 no.5
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• pp.462-468
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• 2010

Carbon Nanotubes (CNTs) have recently emerged as a material with outstanding properties. It has shown promising potential for applications in many engineering fields as electronic devices, thermal conductors, and light-weight composites. Researchers have investigated their use as reinforcements in themetal matrix composites of CNTs. In the present work, we decorated CNTs with Ni particles by electroless plating. The CNTs were wet-ball milled for various milling times with a nickel sulfate solution. The precipitated Ni particles were observed mainly by FESEM. In this study, the dispersion of the CNTs and Ni particles was improved with the addition of the surfactant. Also, as the CNTs were shortened and widened by an increased ball milling time, the size of the precipitated Ni particles increased. It was estimated that the CNTs were deformed and caused some defects on their surface during the ball milling process. Those defects were assumed to be heterogeneous nucleation sites for the Ni particles.